title: The epidemiology of hemorrhage related to cardiothoracic operations.
abstract: OBJECTIVE
  To define the epidemiology, risk factors, and unadjusted cost of hemorrhages related to cardiothoracic operations.
  
  
  METHODS
  We conducted two case-control studies to evaluate the risk of hemorrhage following cardiothoracic operations. The definition of hemorrhage required one of the following: reoperation for bleeding, postoperative loss of greater than 800 mL of blood over 4 hours, or surgeon-diagnosed excessive intraoperative bleeding.
  
  
  METHODS
  The cardiothoracic surgery service of a university hospital.
  
  
  RESULTS
  Of 511 patients undergoing cardiothoracic operations, 93 (18%) met the definition of hemorrhage. In the first case-control study, 3 (14%) of 21 cases and 0 of 42 controls died (odds ratio [OR], 15.0; 95% confidence interval [CI95], 1.18-191.55). Compared with controls, cases received significantly more packed red blood cells intraoperatively (OR, 1.18/100 mL; CI95, 1.01-1.38), and significantly more platelets (OR, 3.26/100 mL; CI95, 1.47-7.26) and fresh frozen plasma (OR, 1.73/100 mL; CI95, 1.05-.84) in the intensive-care unit. Cases were more likely than controls to receive protamine postoperatively (OR, 3.74; CI95, 1.27-11.02). Previous sternotomy, preoperative aspirin or heparin, and preoperative laboratory values did not predict bleeding. The median unadjusted hospital cost was $3,458 higher for patients who suffered hemorrhage than for controls. To decrease costs, hetastarch (acquisition cost $45/500 mL) was substituted for albumin (acquisition cost $76/100 mL) in the pump priming solution (estimated possible cost savings, $7,000-$53,000/year). Because hemorrhage rates increased subsequently, we conducted a second case-control study that identified patient age (P=.02) and use of greater than 5 mL/kg of hetastarch (OR, 1.82) as risk factors for hemorrhage. The cost of treating hemorrhages exceeded all estimates of possible cost savings ($7,000-$53,000 per year).
  
  
  CONCLUSIONS
  Our definition of hemorrhage identified patients who required increased volumes of blood products and who had an increased crude mortality rate and a higher unadjusted cost of hospitalization. Patient age and hetastarch use were risk factors for hemorrhage. Efforts to save money by substituting less expensive products inadvertently may increase costs by increasing the probability of perioperative adverse events.
authors.affiliation: University of Iowa College of Medicine, Department of Internal Medicine, University of Iowa Hospitals and Clinics, Iowa City 52242-1081, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Herwaldt
authors.forename: S K
authors.initials: SK
authors.lastname: Swartzendruber
authors.forename: M B
authors.initials: MB
authors.lastname: Edmond
authors.forename: R P
authors.initials: RP
authors.lastname: Embrey
authors.forename: K R
authors.initials: KR
authors.lastname: Wilkerson
authors.forename: R P
authors.initials: RP
authors.lastname: Wenzel
authors.forename: T M
authors.initials: TM
authors.lastname: Perl
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced / Q000191:economics* / Q000453:epidemiology*; D006746:Hospital Bed Capacity, 500 and over; D006785:Hospitals, University; D006801:Humans; D006895:Hydroxyethyl Starch Derivatives / Q000009:adverse effects / Q000191:economics*; D007484:Iowa / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010952:Plasma Substitutes / Q000009:adverse effects / Q000191:economics*; D011183:Postoperative Complications / Q000453:epidemiology*; D012307:Risk Factors; D019616:Thoracic Surgical Procedures / Q000009:adverse effects*
chemical_list: D006895:Hydroxyethyl Starch Derivatives; D010952:Plasma Substitutes